Hundreds of masked protesters descended on Parliament in a Guy Fawkes-inspired anti-government protest.

Operation Vendetta, organised by hacker-activist group Anonymous, began in Trafalgar Square at about 6pm yesterday.

Tracked by a police helicopter, the group marched down Whitehall to Parliament Square where they launched fireworks into the Palace of Westminster.

Traffic had to be diverted from the east side of the square after a dozen demonstrators lay down in the middle of the road.

Others shouted “shame on you” at police through megaphones and one woman tried to climb the parliamentary compound.

Ten people were arrested for public disorder offences in minor scuffles, but a Metropolitan Police spokesman said it was a peaceful protest otherwise.

By 10.30pm, officers had moved the group back to the grass, allowing the road to be re-opened.

The event was part of a worldwide day of demonstrations and cyber attacks, including a rally in Washington DC, timed to coincide with the anniversary of the failed 1605 gunpowder plot to blow up the House of Lords.

One activist, 28, from north London, who gave his name as Apple Bloom, said: “The date is very symbolic – Guy Fawkes tried to blow up parliament to try to change the system. We are very similar.

“We are not against capitalism, but we want to change capitalism. We want to make it work. The polarity between the rich and poor is getting wider. We want to bring that polarity closer so equality can be achieved.”

Others said they were taking part to protest against web censorship, the government’s austerity measures and the treatment of disabled people.

A nineteen-year-old student from Wiltshire, who referred to himself as Apple, added: “I’m here mainly due to the student cuts.

“My college course is full-time, but it feels like part-time because of the hours. I’m only in three days a week and two of those are half days.

“I want my voice to be heard. I’m standing up for what I think is right.”

Kree Love, 18, a student from South Kensington, said: “People have come to this protest because it is central and it is the best way to get our point across.”

Another student, 19-year-old Cian, from Ireland, said: “I just want to be part of a protest against the government - against the cuts when they are spending billions of pounds on war.”

Police said about 300 people took part in the demonstration, but the group claimed up to 1,500 had been involved.